Isomaltose

Structural formula
General
Surname	Isomaltose
other names	6- O- α- D -glucopyranosyl- D -glucose 6- O -α- D -glucopyranosyl- D -glucopyranose α-1,6-glucobiosis
Molecular formula	C 12 H 22 O 11
Brief description	colorless solid
External identifiers / databases
CAS number 499-40-1 EC number 207-879-1 ECHA InfoCard 100.007.164 PubChem 10357 Wikidata Q2409080
properties
Molar mass	342.30 g mol −1
Physical state	firmly
Melting point	225 ° C (decomposition)
solubility	very easily soluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Isomaltose is a chemical compound belonging to the disaccharide group . It is similar to maltose , but with an α- (1-6) bond instead of the α- (1-4) bond. Both types of sugar are reducing sugars . It arises, among other things, during the digestion of starch and glycogen in the intestine.

Occurrence

Isomaltose occurs as a structural element in amylopectin and glycogen and in free form in honey and starch hydrolyzate .

Extraction and presentation

Isomaltose, along with other compounds, is formed when maltose syrup is treated with the enzyme transglucosidase for several hours and is one of the main components of the isomalto-oligosaccharide mixture, which is used as a food additive.

Isomaltose can also be obtained as a malt extract from barley grains by swelling them in water for 2-3 days and then sprouting for about 10 days. During germination, the reserve strength of the seedling is broken down by amylases , whereby maltose , dextrose and isomaltose are formed. Isomaltose makes up about 5% of the starch component amylopectin .

It is a product of the caramelization of glucose .

It can also be obtained from the partial hydrolyzate of bacterial dextran (as octaacetate), from the enzymatic hydrolyzate of amylopectin and of dextran from Leuconostoc mesenteroides , from maltose by enzymatic transglycosylation and as a reaction product in the reversion of d-glucose with acid.

properties

Isomaltose is a colorless solid that dissolves very easily in water, tastes very sweet and does not ferment or only with difficulty.

Biological importance

In humans, isomaltose is broken down into glucose by the digestive enzyme isomaltase . If this enzyme is not produced in sufficient quantities by the intestinal mucosa , an isomaltose intolerance occurs.

proof

Isomaltose can be detected with Fehling's solution as a reducing saccharide .

Web links

Commons : Isomaltose  - collection of images, videos and audio files

Individual evidence

1. ↑ ^{a b c d} data sheet isomaltose, ~ 98% (TLC) from Sigma-Aldrich , accessed on January 22, 2018 ( PDF ).
2. ↑ ^{a b c d} Entry on isomaltose. In: Römpp Online . Georg Thieme Verlag, accessed on January 22, 2018.
3. ↑ ^{a b} Olof Hammarsten : Textbook of Physiological Chemistry . Springer-Verlag, 2013, ISBN 978-3-662-33750-9 , pp. 174 ( limited preview in Google Book search).
4. ↑ Pocket textbook biochemistry . Georg Thieme Verlag, 2011, ISBN 3-13-165971-8 , p. 167 ( limited preview in Google Book search).
5. ↑ enzymes . Springer-Verlag, 2013, ISBN 978-3-662-30541-6 , pp. 1173 ( limited preview in Google Book search).
6. ↑ BfR: Isomalto-oligosaccharide as a novel food ingredient
7. ↑ R. Hansel, O. Sticher (Ed.): Pharmakognosie - Phytopharmazie . 9th edition. Springer Medicine, Heidelberg 2010, ISBN 978-3-642-00962-4 , p. 457 .
8. ↑ R. Hansel, O. Sticher (Ed.): Pharmakognosie - Phytopharmazie . 9th edition. Springer Medicine, Heidelberg 2010, ISBN 978-3-642-00962-4 , p. 486 .
9. ↑ Hirqshi Sugisawa, Hiroshi Edo: The Thermal Degradation of Sugars I. Thermal Polymerization of Glucose. In: Journal of Food Science. 31, 1966, p. 561, doi: 10.1111 / j.1365-2621.1966.tb01905.x .
10. ↑ Robert Ebermann, Ibrahim Elmadfa: Textbook food chemistry and nutrition . 2nd Edition. Springer-Verlag, Vienna 2011, ISBN 978-3-7091-0210-7 , pp. 38-39 .